# File lib/facter/util/ip.rb, line 140
  def self.get_infiniband_macaddress(interface)
    if File.exists?("/sys/class/net/#{interface}/address") then
      ib_mac_address = `cat /sys/class/net/#{interface}/address`.chomp
    elsif File.exists?("/sbin/ip") then
      ip_output = %x{/sbin/ip link show '#{interface}'}
      ib_mac_address = ip_output.scan(%r{infiniband\s+((\w{1,2}:){5,}\w{1,2})})
    else
      ib_mac_address = "FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF"
      Facter.debug("ip.rb: nothing under /sys/class/net/#{interface}/address and /sbin/ip not available")
    end
    ib_mac_address
  end